Optimal Entangling Capacity of Dynamical Processes

We investigate the entangling capacity of dynamical operations when provided with local ancilla. A comparison is made between the entangling capacity with and without the assistance of prior entanglement. An analytic solution is found for the log-negativity entangling capacity of two-qubit gates, which equals the entanglement of the Choi matrix isomorphic to the unitary operator. Surprisingly, the availability of prior entanglement does not affect this result; a property we call resource independence of the entangling capacity. We prove several useful upper-bounds on the entangling capacity that hold for general qudit dynamical operations, and for a whole family of entanglement monotones including log-negativity and log-robustness. The log-robustness entangling capacity is shown to be resource independent for general dynamics. We provide numerical results supporting a conjecture that the log-negativity entangling capacity is resource independence for all two-qudit unitaries.Comment: Changed title since previous version. 8 pages main text + 4 pages of appendices. Rewritten with some mathematical details moved to appendices. Accepted for publication in Physical Review

Enhanced fault-tolerant quantum computing in dd-level systems

Error correcting codes protect quantum information and form the basis of fault tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transverse non-Clifford gate. Codes with the desired property are presented for $d$-level, qudit, systems with prime $d$. The codes use $n=d-1$ qudits and can detect upto $\sim d/3$ errors. We quantify the performance of these codes for one approach to quantum computation, known as magic state distillation. Unlike prior work, we find performance is always enhanced by increasing $d$.Comment: Author's final copy. Changes includes correction to plot in figure

'Really on the ball': exploring the implications of teachers' PE-CPD experience

Continuing professional development (CPD) is currently high on the Scottish Education agenda. Recent curriculum reform in Scotland, with the introduction of Curriculum for Excellence, places physical education (PE) at the forefront for its role in directly supporting learners' mental, emotional, social and physical well-being. This emphasis on PE, along with concerns about the health of the nation, has resulted in a nationwide initiative providing non-specialist teachers of primary PE with the opportunity to develop a specialism in the subject through government-funded CPD programmes at postgraduate level. Using Knowles' andragogical model as a framework, this paper reports data from a larger research study that evaluated a Scottish PE-CPD initiative. This paper comprises a single case holistic study investigating the impact and implications of a PE-CPD programme through the professional learning journeys, from the outset until completion, of four teachers: a nursery teacher, a class teacher, a cluster cover teacher and a PE specialist who participated in the programme. Data were collected over one academic year using two-stage questionnaire interviews and were analysed thematically with special attention given to the emerging general themes to achieve a holistic understanding of the case. Study findings endorse the positive impact of using the andragogical model of adult learning combined with the literature-supported characteristics of effective PE-CPD programmes. Teachers' perspectives on their CPD experiences, integration of acquired learning into working contexts and teaching post-PE-CPD were then examined to determine the next steps. This led to critical reflection on the implications of the findings for the teachers' ongoing professional development. We then challenged the role that university providers play in supporting teachers' lifelong learning. Instead, we suggest new school-university partnerships and alternative ways to support capacity building and lifelong learning towards a sustainable transformational change in Scotland's primary PE

Distributed quantum information processing with minimal local resources

We present a protocol for growing graph states, the resource for one-way quantum computing, when the available entanglement mechanism is highly imperfect. The distillation protocol is frugal in its use of ancilla qubits, requiring only a single ancilla qubit when the noise is dominated by one Pauli error, and two for a general noise model. The protocol works with such scarce local resources by never post-selecting on the measurement outcomes of purification rounds. We find that such a strategy causes fidelity to follow a biased random walk, and that a target fidelity is likely to be reached more rapidly than for a comparable post-selecting protocol. An analysis is presented of how imperfect local operations limit the attainable fidelity. For example, a single Pauli error rate of 20% can be distilled down to $\sim 10$ times the imperfection in local operations.Comment: 4 pages of main paper with an additional 1 page appendix, 5 figures. Please contact me with any comment

Gaussification and entanglement distillation of continuous variable systems: a unifying picture

Distillation of entanglement using only Gaussian operations is an important primitive in quantum communication, quantum repeater architectures, and distributed quantum computing. Existing distillation protocols for continuous degrees of freedom are only known to converge to a Gaussian state when measurements yield precisely the vacuum outcome. In sharp contrast, non-Gaussian states can be deterministically converted into Gaussian states while preserving their second moments, albeit by usually reducing their degree of entanglement. In this work - based on a novel instance of a non-commutative central limit theorem - we introduce a picture general enough to encompass the known protocols leading to Gaussian states, and new classes of protocols including multipartite distillation. This gives the experimental option of balancing the merits of success probability against entanglement produced.Comment: 4 + 4 pages, final versio

Aircraft rotor blade with passive tuned tab

A structure for reducing vibratory airloading in a rotor blade with a leading edge and a trailing edge includes a cut out portion at the trailing edge. A substantially wedge shaped cross section, inertially deflectable tab, also with a leading edge and a trailing edge is pivotally mounted in the cut out portion. The trailing edge of the tab may move above and below the rotor blade. A torsion strap applies force against the tab when the trailing edge of the tab is above and below the rotor blade. A restraining member is slidably movable along the torsion strap to vary torsional biasing force supplied by the torsion bar to the tab. A plurality of movable weights positioned between plates vary a center of gravity of the tab. Skin of the tab is formed from unidirectional graphite and fiberglass layers. Sliders coupled with a pinned degree of freedom at rod eliminate bending of tab under edgewise blade deflection

Optimum satellite orbits for accurate measurement of the earth's radiation budget, summary

The optimum set of orbit inclinations for the measurement of the earth radiation budget from spacially integrating sensor systems was estimated for two and three satellite systems. The best set of the two were satellites at orbit inclinations of 80 deg and 50 deg; of three the inclinations were 80 deg, 60 deg and 50 deg. These were chosen on the basis of a simulation of flat plate and spherical detectors flying over a daily varying earth radiation field as measured by the Nimbus 3 medium resolution scanners. A diurnal oscillation was also included in the emitted flux and albedo to give a source field as realistic as possible. Twenty three satellites with different inclinations and equator crossings were simulated, allowing the results of thousand of multisatellite sets to be intercompared. All were circular orbits of radius 7178 kilometers

Student Mastery of Engineering with Design Review

Traditional structural engineering pedagogy has consisted of students preparing for class by reading a textbook, followed by a professor giving a lecture, followed by students doing individual homework. Students received feedback in terms of a grade from the professor, and, ideally, the student filed the graded work and possibly reviewed it again before an exam. Following the exam, the professor moved to the next topic and essentially ended any further contact time with the material, resulting in students quickly dumping a good percentage of what was learned. To make matters worse, most faculty would agree that undergraduate students often skip the reading prior to class, and studies have shown that almost half of all students do not pay attention to material presented during a lecture. Thus, it is critical for engineering educators to improve the stagnant method of traditional teaching and learning. Small mistakes in the engineering profession can lead to death or millions of dollars in repair. For the fall 2018 semester, in the Design of Steel and Wood Structures at the United States Military Academy at West Point, Civil Engineering students participated in a cooperative learning technique aimed at improving student learning. These same students tried a different version of this technique in Structural Analysis the prior semester.[1] Prior to submitting individual homework to the instructor for grade, students paired up with a peer within their class hour and checked each other’s work using an instructor provided “Design Review Sheet.” When a student found a mistake, or disagreed with the methodology used by their Design Review partner, the student annotated this on their sheet. The expectation was that when disagreements were discovered between students, they would discuss with each other where the error or misunderstanding existed and subsequently corrected the error prior to submission for grade. This not only required students to explain the work they completed, but it also provided additional contact time with the material. With respect to Engineering Teaching and Learning, Design Review provides the essential cooperative learning characteristic of positive interdependence because individual student learning increases as review partners improved in their Design Review. As a student incentive to complete a thorough review, the quality of review counted for 10% of each assignment. Efforts this iteration were in response to some of the student suggestions following a previous iteration.[1] This iteration, in lieu of students turning in their work in pairs to receive one grade, each student would turn in their individual work and Design Review sheet. This was done to hold all students accountable for the work they completed. In addition, the instructor provided Design Review sheet was modified for clarity and the requirement to write a memorandum summarizing the results of each Design Review was eliminated. This cooperative learning technique was used on six of seven homework assignments during the term and on seven of nine homework assignments in their pre-requisite course. Student feedback was collected from both Likert Scale questions and open-ended questions. This paper will make the case that this pedagogy benefits Engineering Teaching and Learning by: (1) getting engineering students in the practice of what engineers in practice already do (check each other’s work), (2) increasing student learning of course learning objectives through repetition and through observing how others solve problems and present their work, and (3) improving the ability of future engineers to communicate their work clearly and effectively.Cockrell School of Engineerin

Physical properties of the Apollo 12 lunar fines

Optical and radio frequency electrical properties and grain size analyses of Apollo 11 and 12 lunar soil sample